Telemetric system



Nov. 2, 1943- w. E. DUE RINGER- l 2,333,083 TELEMETRIC SYSTEMS I Original Filed May 28, 1957 5 Sheets-Sheet 1 a P I t 2| Fm; 2 INVENTOR WALTER E. DUERINGER .4 1.0. -mORNEW Nov. 2, 1943; w. E. ESUERINGER TELEMETRIC SYSTEMS -Qriginal Filed May 28, 1937 5 Sheets-Sheet 2 INVENTOR WALTER E DUERINGER I 4 ATTORN 'Fne. 6

5 Shee ts-Sheet 5 FIG.

TELEMETRIC SYSTEMS Original Filed May 28. 1937 Nov. 2, 1943. 3

BY WALTER E. DUERINGER FIG. 9

Nov. 2, 1943.

W. E. DUERINGER TELEME'I'RIC SYSTEMS Original Filed May 28, 1937 5 Sheets-Sheet 4 FIG. I I

INVENTOR BY WALTER E. DUERINGER 9. ATTOR Y Nov. 2, 1943.

W. E. DUERINGER TELEMETRIC SYSTEMS Original Filed May 28, 1937 5 Sheets-Sheet 5 Jnventgr WALTER E. DUERINGER Mann;

Patented Nov. 2, 1943 TELEMETRIC SYSTEM v V I Walter E. Dueringer, Shaker Heights, Ohio, as-

signor to Bailey Meter Company, a corporation of Delaware Original application May 28, 1937, Serial No. 145,284. Divided and this application October 30, 1940, Serial No. 363,536

Claims.

This invention relates to telemetric systems for remotely indicating or otherwise exhibiting the position of a movable transmitting member.

One object of my invention is to provide a system wherein the position of a delicate sensitive member, such as a Bourdon tube or 89.1- vanometer, may be remotely indicated or otherwise exhibited.

A further object is to provide a telemetric system wherein the sum or diflerence of a plurality of indications may be determined and exhibited at a remote station.

Still another object is to provide a telemetric system wherein the position of a movable transmitting member may be exhibited at a plurality of remote receiving stations.

It is a further object to provide a telemetric system wherein the indication at the receiving station is unaffected by changes in conditions otherwise afiecting the accuracy with which the transmitting member is positioned.

Further objects will be apparent from the description and from the drawings in which:

I indicator I is secured may be positioned, for ex- Fig. 1 illustrates a transmitting station embodying my invention.

Fig. 2 illustrates a receiving station used with the transmitting station shown in Fig. 1.

Fig. 3 is a wiring diagram of the electrical connections used with the apparatus shown in Figs. 1 and 2.

Figs. 4 and 5 are modified forms of my invention as shown in Fig. 1. I

Fig. 6 is a detailed view of part of the mechanism shown in Fig. 5.

Fig. 7 illustrates my invention employed to totalize a plurality of Indications.

Figs. 8 and 9 are modified forms of my invention as shown in Fig. '7.

Fig. 10 is a schematic wiring diagram illustrating the invention used to exhibit the position of a movable transmitting member at a plurality of remote receiving stations.

Fig. 11 is a fragmentary view illustrating a modified form of the apparatus shown in Fig. 1 used with the modification of my invention embodied in Fig. 10.

Figs. 12 and 13 are fragmentary views of modified forms of Fig. 1 incorporating means for correcting for changes in conditions otherwise affecting th accuracy with which the transmitting member is positioned.

Referring to the drawings, Fig. 1 represents a transmitting station within which is a pointer or indicator I angularly positionable about a proportional to, or in relation to, the position of,

ample, by a Bourdon tube responsive to pressure or temperature, a meter of the rateoi fiowof a fluid, a galvanometer responsive to'an electromotive force: or by any other device positioned by and in accordance with the magnitude of a variable. The spindle 2 may, in some cases, be positioned manually, so that the pointer I, positioned to difierent points on the scale 3, indicates various orders, commands, or other information it is desired to transmit toa remotely located station.

Fig. 2 represents a receiving station and is provided with an index 4 positionable about a shaft 5. Cooperating with the index 4 is a scale 5 which may be graduated identically with scale 3. In general, it is the purpose of the apparatus shown in Figs. 1 and 2 to position the index 4 in accordance with changes in position of the transmitting index I, so that an observer stationed at the receiving station shown in Fig. 2, will be immediately advised of the position of the transmitting index I.

The mechanism shown in Fig. 1 acts to periodically originate electrical impulses of a time length or change in position of, the transmitting index I. Likewise the mechanism shown in Fig. 2 acts to periodically originate electrical impulses of a time length proportional to, or in.relation to, the

position of, or change in position of, the receiving index 4. If these electrical impulses originat-i ing in the transmitting and receiving mechanisms are of the same time length it indicates that the position of the receiving index 4 agrees with that of the transmitting index I. If, however, the impulses originating in the transmitting mechanism are of either shorter or longer duration than those originating in the receiver, it indicates that the receiving index 4 is not in agreement with the transmitting index I. Accordingly, incorporated in th receiving mechanism are means for positioning the receiving index 4 an amount proportional to the difference in time lengths of the spindle 2, and the position of which relative to a impulses and in a sense to restore correspondence between the transmitting and receiving indices.

In the transmitting mechanism shown in Fig. 1 these electric impulses are originated through the agency of a contact 1 carried by a member 8, one end of which is pivotally supported by a shaft 9 and the other end of which is periodically reciprocated by a cam Ill mounted on shaft IDA and continuously rotated by means of a synchronous motor I I. Engaged by the contact I during each cycle of operation is a contact I2 carried by a pick-up member I3, pivotaily supported on the shaft 9. The member I3 has an extension I4 normally resting by gravity on an arm I5 positionable about the shaft 9 by an extension iii of the transmitting index I through a link ISA. When the transmitting index I is positioned upwardly, for example, the arm I5 is positioned about the shaft 9 in a counterclockwise direction a proportionate amount, carrying with it the member I3. Likewise when the transmitting index I.is positioned downwardly the arm I5 is positioned in a clockwise direction a proportionate amount, carrying with it the member I3. The increment of time during each cycle of operation in which contacts I, I2 are engaged is therefore dependent upon the position of the arm I5.

In the receiving station is a cam I'I continuously rotated in phase with the transmitting cam III by a synchronous motor I8 and serving to periodically reciprocate a member I9 about a shaft 20. The member I9 carries a contact 2I arranged to engage a cooperating contact 221 carried by a pick-up member 23 pivotally mounted on theshaft 20. The member 23 is provided with an extension 24 normally resting by gravity on a lever 25 positionable about the shaft 20 and connected to the receiving index 4 through a link 29. The arm 25 has an extension 21 connected by a link 28 to a reversible motor 29 having opposed windings. Movement of the motor 29 in a clockwise direction effects a downward positioning of the receiving index and a corresponding positioning of the member 23. Conversely counter-clockwise positioning of the motor effects an upward positioning of the receiving index 4 and member 23. I

If the position of the receiving index 41 cortact I2 before the contact 2I engages the contact 22 by a length of time proportional to the downward movement of the transmitting index I.

Referring now to Fig. 3 I have shown the electrical connections within and between the receiving and transmitting stations. The contacts I, I2 act, upon engagement, to short circuit a winding 30 of the reversible motor 29. The contacts H, 22, upon engagement, act to short circuit the opposed winding III of the motor. With the winding 30 short circuited the'motor 29 rotates in one direction, with the winding 3| short circuited the motor rotates in opposite direction. With both windings either energized or deenergized the motor is not urged to rotation in either direction. It is apparent that upon the contact I engaging the contact I2 simultaneously with the engagement of contacts 2I and 22 the motor 29 will remain stationary. However, if the contacts I, I2 engage prior to engagement of contacts 2|, 22 the motor will rotate in one direction, and if contacts 2|, 22 engage prior to contacts 'I, I2 the motor will rotate in opposite direction until the lagging pair of contacts engage. Rotation of the motor 29 as hereinbefore explained serves to position the contact 22 and the receiving index 4. Simultaneous engagement of contacts 'I, I2 and 2|, 22 indicates that the position of the receiving index 4 is in correspondence with that of the 5 transmitting index.

Connected in the neutral of the motor 29 is a mercury switch 32 pivotaily supported on a bracket 33 and arranged to be rocked from a closed toan open position when a predetermined point on the rising section of cam II is engaged by member I9. Upon the member I9 engaging substantially the lowermost point of cam II, the switch 32 is thrown to closed position. When as shown in Fig. 2 the member I9 is engaging the rising section of cam II the mercury switch 32 is closed so that engagement of contacts 2I, 22 and/or contacts I, I2 serves to short circuit the windings of the motor 29. Upon the member I9 being raised-*to a predetermined position by the cam II the mercury switch 32 will be tilted to open position, thereby open circuiting the windings 29 and notwithstanding that the contacts 2|, 22 and I, I2 remain engaged. After member I9 has passed below the lowermost position in the range 5 of operation of the member 23, thereby obviating the possibility of contacts I and 2I being engaged with their cooperating contacts I2 and 22 respectively, mercury switch 32 is thrown to closed position.

30 In normal operation cam II is in exact phase with the cam III. That is the point on the contour of 0am I'I engaged by the member I9 agrees precisely with the point on the contour of cam I0 engaged by member 8. Under these conditions it is apparent that if indices I and 4 are in proper correspondence contacts 2I, 22 and I, I2 will enindex 4 downwardly. If the change in position of the index 4 is suflicient to again bring it into correspondence with the index I, upon the next cycle of operation the contacts 2I, 22 and I, I2 will engage simultaneously. If, however, the correction has not been sufficient to reestablish correspondence, then the contacts I, I2 will again to engage before contacts 2I, 22 but by a smaller increment of time. Each cycle of operation will, if necessary, produce a similar incremental positioning of the index 4 until it is brought into proper correspondence with index I. Upward movement of the index I produces converse action, the contacts 2I, 22 then engaging prior to the contacts I, I2, actuating the motor 29 in a I direction to position the index 4 upwardly until it is again brought into proper correspondence With the transmitting index I.

While under normal operating conditions the cams I0 and II will remain in proper phase relationship indefinitely, to insure such phase relationship being continuously maintained, the position of the cam II is compared to that of the cam Ill each revolution, and if it is out of phase ber I9 engages lateral contact 36 disengages contact 35.

projection 42 of. cam I1,

39 leaving projection 4I contacts 31, 38 disengage and upon section 40 leaving projection 42 contacts 35, 36 reengage. If cam I! is in proper phase relationship with cam I contacts 31, 38 will engage at the instant contacts 35, 36 disengage; and disengagement of contacts 31, 38 and reengagement of contacts 35, 36 will also occur simultaneously, thereby effecting continuous energization of the motor' I8. If cam I1 is out of phase with cam I0 then such coordinated action between contacts 35, 36 and 31, 38 will not occur resulting in the motor I8 being .deenergized periodically or continuously until proper phase relationship is again restored.

Telemetric systems such as I have disclosed in Figs. 1, 2 and 3 I use to remotely indicate or otherwise exhibit the magnitude of a condition, such as pressure, temperature, or electromotive force. Devices sensitive to such conditions are inherently delicate, and in order that they may accurately be positioned in accordance with the magnitude of the condition being measured it is necessary that the transmitting mechanism does not in any way react upon them. To avoid the possibility of such reaction destroying the accuracy with which the transmitting index I is positioned, I show in Fig. 1 a preferred form of locking means whereby the arm I5 is locked in position while being engaged or disengaged by the extention I4. Accordingly, any reaction or shock which might otherwise be present, due

Upon section to the per odic lifting and falling of the member I3, is eliminated.

Referring to Fig. 1, there is secured to the arm II a brake drum 43. Cooperating therewith is a brake band or shoe 44, normally held in engagement with the drum by the weight of an overhanging arm 45. During each cycle of operation after the member I3 has been lifted from the arm I5 the extension I4 engages the arm 45 and releases the brake band 44, so that the arm I! isfree tobe posit oned by the Sensitive device moving the spindle 2. Preferably the brake band 44 is released only after the member 8 has been moved beyond the limits within which the member I3 is positioned by the sensitive device. Upon the member 8 descending, the brake band 44 is aga n brought into engagement with the drum 43 before the extension I4 engages the arm I5. Accordingly, any slight shock which m ht otherwise be transmitted to the spindle 2 throu h engagement of the extension I4 withthe arm' I5 is avoided. I

In Fig.4 I show a modified form of brake mechanism wherein the drum 43 is normally engaged by a brake shoe 46 having one end p votally mounted on a stationary shaft 41 and provided with a substantially horizontal arm 48 which normally serves through its weight to hold the band 46 in engagement with the drum 43. Axiallv mounted on the arm 48 is a cam follower 49 adapted to be lifted by raised section 50 of a cam 5| and disengage the shoe 46 from the drum 43. The cam 5| is mounted On the shaft IDA and rotates in un son with the cam I0. Preferably the raised section 50 is arran ed so that the shoe 46 is disenga ed from the drum 43 onlv when themember I3 is beyond the travel limit of the arm I5, However, as will be apparent to those skilled in the art, the raised section 50 may be proportioned to give any desired relation between the periods of t me when the drum 43 is engaged and disengaged by the shoe 46.

, mitting indices 62, 63 and .means. Pivotally supported by the extension I4 is a contact arm 52' normally resting againsta bracket 53 carried by the member I3. The arm 52 carriesa contact 54 adapted to engage a contact 55 carried by the member 8. Engagement of the contact 55 with the contact a solenoid 56.

The arm, I5 is provided with a brake sector 57. As shown in Fig. 6, the brakesector 51 is adapted to be engaged by a brake shoe58 pivotally supported at 59. Normally the shoe '58 is held out of engagement with the sector 5! by a tension spring 68. Upon energization of the solenoid 56, however, the shoe 58 is brought into engagement with the sector 51 by a plunger SI urged to the left, as viewed in the drawings.

As will be apparent from Fig. 5, contacts 54 and 55 engage during a predetermined increment of time prior to the engagement of contacts I and I2. Likewis they are disengaged after contacts I and I2 have disengaged. Accordingly, the arm I5 will be free to be positioned by the 'responsive device excepting for a period of time overlapping the increment of time when the contacts I and I2 are in engagement. It is frequently desirable to remotely indicate the total of difference of a plurality of variables. Particularly in the measurementof the rate of flow of fluids, suohas, steam, water, or gas, it is desirable to know the total flow through a plurality of lines. In Figs. 7, 8 and 9 I have disclosed alternate arrangements of my invention adapted to remotely give the sum of a plurality of variables. Referring to Fig. 7, I therein show trans-v 64, eacharranged to be positioned relative to a scale and each resp0nsive to a variable such as the rate of flow of a fluid through a conduit. Actuated by the transmitting indices 62, 63 and 64 are transmitting devices, such as shown in Fig. 1, diagrammatically illustrated at 65, 66 and 61 respectively. The transmitting device serves to position a receiving device, such as shown in Fig.\2, diagrammatically illustrated at 68. The receiving device 68 is provided with an arm 69, corresponding to the index 4 shown in Fig. 2, and positioned in consonance with the positioning of the transmitting index 62. Depending from the arm 69 is a pivoted link 10 and depending from the. transmitting index 63 is a similar arm II. Links III and II are pivotally connected to a horizontal differential beam I2, from themidpoint of which dependsa. pivoted member I3, serving to actuate an arm 14, corresponding to the transmitting index I shown in Fig. l, and controlling the transmitting device 66.

The transmitting device 66 is therefore positioned jointly by the transmitting index 63 and arm 69, so that itoriginates electrical impulses proportional to the sum of the pos tions or changes in position of the transmitting index 63 and arm 69.

The transmitting device 66 in turn serves to 54 energizes position a receiving device I5 differentially linked by means of a member I6 to the tran m tting index 64, and the two serving to jo ntly position the transmitting mechanism 61. The transmitting mechanism 61. accordingly originates impulses proportional in time length to the sum of the positions or changes in position of the transmitting indices 62, 63 and 64. Such impulses are transmitted to a final receiving mechanism "(having an index 18, which is positioned in accordance with the sum of the P sitions of the transmitting indices 62', 63 and "64. An ob- 7 server, therefore, stationed at the receiving mechanism 11 may, by observing the position of the final receiving index 18, be advised of the total of the variables which th indices 62, 63 and 64 are positioned in accordance with.

' In Fig. 8 I show a modified arrangement adapted to remotely indicate, or otherwise exhibit the sum of four variables. Therein I show transmitting indices 19, 88, 8| and 82, each positioned I in accordance with the magnitude of a variable.

I which in turn controls a final receiving mechanism 9|. The receiving mechanism 9| may be provided with a final receiving index 92 which will be positioned relative to a scale 93 in accordance with 'the sum of the positions of the transmitting indices 19, 88, BI and 82.

In Fig. 9 I show an alternate arrangement wherein transmitting indices 94, 95, 96 and! actuate transmitting devices 98, 99, I88 and I8I respectively. Positioned by the transmitting mechanisms are receiving devices I82, I83, I84 and I85 respectively, which may be remotely located from the transmitters.

Receiving devices I82 and I83 jointly serve to position a differential gear mechanism diagrammatically indicated at I86. Likewise receiving devices I84 and I85 serve to actuate a differential gear mechanism I81. Differential gear mechanism I86 positions a shaft I88 and differential gear I81 positions a shaft I89, which together serve to actuate a differential gear mechanism H8. Operated by the difl'erential gear mechanism H8 is a worm III positioning an index 2 relative to a scale H3. The index II2 will be positioned proportional to the sum of the positionings of the transmitting indices 94, 95, 96 and 91.

In Fig. 10 I show diagrammatically an arrangement whereby a single transmitting mechanism may be used to position a plurality of receiving mechanisms. Therein I show a transmitting mechanismgenerally indicated at I I4 arranged to position a receiving mechanism H5 and a second receiving mechanism II6. Located within the receiving mechanism H5 is a reversible motor II1, similar to motor 29 and having opposed windings H8 and H9. Winding H8 is controlled by contacts I28 and I2I, corresponding to contacts I and I2 shown in Fig. 1. Periodically contact I28 engages contact I2] and serves to short circuit winding I I8. Winding I I1 is controlled by contacts I22 and I23 located in the receiving mechanism H5 and corresponding to contacts 2I and 22 shown in Fig. 2/ If contacts I28, I2I and I22, I23 engage simultaneously, motor H1 is not urged to rotation in either direction. If contacts I28, I2I engage before contacts I22, I23 motor II1 rotates in one direction, and conversely if contacts I28, I2I engage after contacts I 22, I23 motor II1 rotates in the opposite direction.

Within the receiving mechanism H6 is a reversible motor I24 similar to motor 29 and having opposed windings I25 and I26. Winding I26 is controlled by contacts I28, I2I simultaneously with winding H8 or motor II1. Winding I25 is controlled by contacts I21, I28 located in the receiving mechanism I I6 and corresponding to contacts 2I, 22 shown in Fig. 2. Accordingly, so long as contacts I21, I28 engage simultaneously with contacts I28, I2I the motor I24 is not urged to rotation. Engagement of contacts I28, I2I subsequent to or prior to engagement of contacts I21, I28 serve to produce rotation of the motor I24 in one direction or another to restore simultaneous engagement of the transmitting contacts I28, I2I and receiving contacts I21, I28.

It is, of course, understood that at the transmitting station II4 a mechanism similar to that shown in Fig. 1 would be located and serve to actuate contact I28, I2I. In each of the receiving stations H5, H6 a receiving mechanism similar to that shown in Fig. 2 would be located and serve to position the contacts I22, I23 and I21, I28 respectively. In each of the receiving mechanisms H5, H6 is located a mercury switch I29 and I38 respectively To open the neutral of the motors H1 and I24 when contacts I22 and I21 attain predetermined positions and similarly to close the neutrals upon said contacts attaining second predetermined positions.

In order that motors I3I and I32 located in I receiving stations H5 and H6 respectively and corresponding to motor I8 shown in Fig. 2, may be maintained in proper phase relationship with motor I33 located in transmitting station I I 4 and corresponding to motor II shown in Fig. 1, I provide means as shown in Fig. 1 for checking the phase relationship between said motors each cycle of operation. Located within receiving station II5 are normally engaged contacts I34 and I35, and in receiving station II6 similar contacts I36 and I31. Connected in parallel with contacts I34, I 35 are contacts I38 and I39 located in the transmitting mechanism II4. If the motor I3I is in proper phase relationship with motor I33 the instant contacts I34, I35 become disengaged contacts I38, I39 engage and the instant conodtween the operation of contacts I34, I35 and I38,

I39 will not occur and the position of motor I3I is corrected until the proper phase relationship is restored.

Operated in unison with contacts I38, I39 are contacts I48, I4I, connected in parallel with contacts I36, I31 located in the receiving station I I6. These contacts serve to control the operation of motor I32 to maintain it in proper phase relationship with motor I33. In Fig. 11 I show how the transmitting mechanism shown in Fig. 1 may be modified to include contacts I48, I4I. Therein the member 8 carries. contacts I39, I4I arranged to engage contacts I38 I48 carried by the member 38A. Once each revolution of the cam I8 when the extension 39 engages the lip 4| contacts I38, I39 and I48, I4I will engage,

Devices for determining the magnitude of some particular variables are affected by conditions pertinent to that variable and my invention further contemplates correcting the position of the aesaoae responsive device so that the arm I 6 and accordingly the receiving index 4 are moved in exact accordance with changes in the variable and errors which would otherwise be present are eliminated. For example, in a meter for determining the rate of flow of fluid through a conduit, the pressure differential produced byan orifice and by which the meter is positioned is affected by changes in pressure and temperature of the fiuid being measured. Specifically:

h ix t Where:

W=rate of flow of fluid in pounds per hour.

=2. constant.

h=difierential head in inches of water.

V=speciflc volume in cubic feet per lb.

It is apparent that variations in any condition afiecting the specific volume of the fluid will affeet the accuracy with which the responsive device is positioned. For compressible vapors and gases such conditions are usually pressure and temperature, for non-compressible fluids, such as water, variations in temperature usually produce the greater error. Where my telemetric system is used to remotely indicate the magnitude of such variables I provide means for modifying the positioning of the arm I5 in accordance with changes in the magnitude of the condition or conditions.

Referring to Fig. 12, fastened to the spindle 2 is a drive arm I50 in which is an arcuate slot I5I. Positionable in the slot I5I is one end of a horizontal beam I52, the other end of which is pivotally connected to a link I53 secured to and positioning the arm I5. Depending from the beam I52 is a pivoted member I54, the lower end of which is connected to a lever I55 positionable about a fixed pivot I56 by a cam I5'I engaging a follower I58 rotatably mounted on the lever.

The cam I5! is movable about a fixed pivot I59 by a Bourdon tube I60 through a link I6I.

The Bourdon tube I60 may be responsive to pressure or temperature affecting the positioning of the spindle 2 by the variable which it is desired to remotely indicate. It should be understood, however, that the Bourdon tube I60 is merely one example of any number of devices which may be used to modify the positioning of the arm I5 by spindle 2.

In operation, assuming that the Bourdon tube I60 remains in fixed position, then movements of the spindle 2 are transmitted to the arm I5 through members I50, I 52 and I53. Assume now that the Bourdon tube I60 is deflected in a counterclockwise direction a predetermined amount, then the lever I55 will rise a predetermined amount depending upon the contour of the cam I61. Member I 52 will accordingly be positioned upwardly in the slot I5I and thereafter a given angular motion of the spindle 2 will produce a smaller amount of angular positioning of arm I5 than it did previously. Conversely, if the free end of the Bourdon tube I60 is positioned in a clockwise direction then beam I52 will be positioned downwardly, thereby increasing the resultant motion of arm I5 for a given motion of spindle 2. It is apparent that by proper shaping of the cam I5! any desired relation may be obtained between changes in the magnitude of the condition positioning the Bourdon tube I60 and resultant changes in the ratio between movements of the spindle 2 and arm I5.

Referring to Fig. 13 I show a modification wherein the ratio between angular movements of the spindle 2 and arm I5 is varied in accordance with changes in magnitude of two conditions. In the measurement of the rate of flow of steam,

for example, the differential head produced by an orifice or other primary element varies inversely as the specific volume. Inasmuch as the spindle 2 is angularly positioned in accordance with the diiferential head, if the remote index 4 is to be positioned in exact accordance with the rate of flow, it is necessary that the movements imparted to the arm I5 by the spindle 2 be modified both in accordance with changes in temperature and changes in pressure, inasmuch as changes in both of these conditions affect the specific volume.

In Fig. 13 the link I54 is shown pivotally connected to a differential beam I62, one end of which is positioned by a'Bourdon tube I63 connected by the capillary I64 to a temperature sensitive bulb I65. As will be understood by those familiar with the art, the bulb I65 is installed in the conduit through which the fluid, the rate of flow of which it is desired to determine, is flowing. The Bourdon tube I63 will thereafter be positioned in accordance with changes in temperature of the fluid surrounding the bulb I65.

The opposite end of the differential beam I62 is positioned by a Bourdon tube I66 connected by a tube I61 to the conduit (not shown). Inasmuch as the specific volume of steam varies directly with increases in temperature and inversely with increases in pressure, the Bourdon tube I63 sensitive to temperature is arranged to position the beam I 62 upwardly in the slot I5! as the temperature of the steam increases. Likewise the Bourdon tube I66 sensitive to pressure is shown arranged to position the beam I52 down.- wardly in the slot I5I upon increases in pressure.

It is to be understood, of course,-that I have used the measurement of the rate of flow of steam .merely as an example and that the apparatus shown in Fig. 13 may be put to a wide variety of uses. In general, it may be used to multiply or divide the angular motion of the spindle 2 imparted to the arm I5 in accordance with changes in one or more conditions regardless of what those conditions might be.

Having thus described my invention and preferred embodiments thereof, I desire it to be 1111- derstood that I am not to be limited thereby except asto the claims in view of the prior art.

This application constitutes a division of my copending parent application Serial No. 145,284,.

filed in the United States Patent Office May 28, 1937.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a telemetric system, in combination, a member positioned in accordance with the magnitude of a variable, cyclically operable means for periodically determining the position of said member, and additional means locking said first named member in position during a predetermined portion of each cycle of operation.

2. In a telemetric system, in combination, a first member angularly positionable about a center, a second member positionable about said center and normally in engagement with the first member, cyclically operable means for periodically moving the second member from engagement with the first member to a predetermined position and returning it to said normal position, and additional means for locking said first member against movement while the second member is in engagement therewith.

3.,In a telemetric system, in combination, a first member engularly positionable about a center, a second member positionable about said F center and normally in engagement with the first member, cyclically operable means for-periodically moving the second member from engagement with the first ember to a predetermined position and returnil; it to said normal position, and brake means ocking said first member against movement operated by the second member at predetermined points in its movement by said cyclically operable means.

4. In a telemetric system, in combination, an axle, a first member angularly positionable about said axle, a second member positionable about said axle and normally in engagement with the first member, cyclically operable means for periodically moving the second member from engagement with the first member to' a predetermined position and returning it to said normal position, a brake drum secured to first member and rotatable about said axle, a cooperating brake band arranged to engage said drum, an arm secured to said band for normally maintaining said band in engagement with said drum, and a. projection on the second member for engaging said arm to release said band from engagement with the drum.

5. In a telemetric system, in combination, an

- axle, a first member angularly positionable about said axle, a second member positionable about said axle and normally in engagement with the first member, cyclically operable means for peri odically moving'the second member from engage-- ment with the first member to a predetermined first member, cyclically operable means for peri-' odically moving the second member from engagement with the first member to a predetermined position and returning it to said normal position,

and cyclically operable brake means for periodlcally locking said first member against rotation for predetermined increments of time.

7. In a telemetric system, in combination, an axle, a first member angularly positionable about said axle within predetermined travel limits, 9. second member positionable about said axle and normally in engagement with the first member, a rotatable cam for periodically moving the sec- 0nd member from engagement with the first Jnember to a predetermined position beyond said member, an electromagnetic retarding means for locking said first member in position during a predetermined portion of each cycle of operation.

9. In a telemetric system, in combination, a first member angularly positionable about a center, a second member positionable about said center and normally in engagement with the first member, cyclically operable means for periodically moving the second member from engagement withthe first member to a predetermined position and returning it to said normal position, and electromagnetic brake means under the control of said cyclically operable means for locking said first member in position during a predetermined portion of eachincrement of time.

10. In a telemetric system, in combination, an

axle, a first member angularly positionable about said axle, a second member positionable about said axle and normally in engagement with the first member, a rotatable cam for periodically moving the second member from engagement with the first member to a predetermined position and returning said second member to engagement with the first member, an electromagnetic means under the joint control of the second member and the cyclically operable means for locking the first member against movement while the-second member is being engaged or disen- WALTER E. DUERINGER. 

